Even this feels too extreme for me.  I think users would hate it.  They
did an ifup and swapped cables.  They expect the OS/Driver/Firmware
to continue trying to honor their ifup request.

Lets take a look around at other subsystems....

What happens if you hot-unplug a SATA drive?
An MMC card?
A USB device?
A PCIe card?
A CPU?
An SDRAM?

Do you know of any subsystem that tried to keep its configuration
across a hot unplug/plug event? I suspect they all require user space
to take some action to get the newly plugged hardware into operation.

       Andrew